The present invention is related to an improved slide cover unit which is applicable to a small-size product. The slide cover unit has simple structure and can be smoothly opened/closed.
A mobile phone is often equipped with a slide cover unit for avoiding mis-touch of the keyboard and protecting the keyboard from being directly collided and damaged. FIGS. 1 and 2 show a typical slide cover unit including an upper cover 11, a substrate board 12, a torque spring 13, an arc restricting plate 14 and an extension spring 15. The upper cover 11 is formed with slide rails 113 slidably fitted on the substrate board 12. An upper face of the upper cover 11 is formed with a slot 111 and a sunk hole 112 communicating with the slot 111. One end of the extension spring 15 is fixed at a head end of the slot 111, while the other end of the extension spring 15 is connected with a roller 16 inlaid in the sunk hole 112. One end of the arc restricting plate 14 is connected with the roller 16. One end of the torque spring 13 is fixed on a fixing block 17.
One side of the substrate board 12 is formed with a fixing hole 121 in which the other end of the torque spring 13 is fixed. Two sides of the substrate board 12 are respectively formed with slide channels 122 in which the slide rails 113 are inlaid. The other end of the arc restricting plate 14 is disposed on one side of the substrate board 12 opposite to the fixing hole 121, whereby the arc restricting plate 14 can swing.
Referring to FIGS. 2 to 4, when the upper cover 11 moves downward by a travel, the arc restricting plate 14 swings downward as shown by phantom line of FIG. 3. At this time, the roller 16 is moved rightward and the extension spring 15 is extended to exert a pulling force onto the roller 16. The torque spring 13 is shifted and compressed (as shown by phantom line of FIG. 3) to conserve a resilient energy. Due to the elasticity of the torque spring 13, the upper cover 11 is kept in an upper position. However, when the fixing block 17 of the upper cover 11 passes over the level of the fixing hole 121, the torque spring 13 is further moved downward and restored from the compressed state into the original state (as shown by phantom line of FIG. 4). At this time, the resilient energy is released to move the upper cover 11 downward. Simultaneously, the arc restricting plate 14 swings downward and the extension spring 15 is compressed to locate the upper cover 11 in a lower position as shown in FIG. 4. The above structure is complicated and it is troublesome to assemble these components. As a result, the manufacturing cost is higher. Moreover, the complicated structure leads to enlarged volume and heavy weight.
FIGS. 5 and 6 show another type of conventional slide cover structure. The slide cover includes a substrate board 22, an upper cover 21 disposed on one side of the substrate 22, two springs 23 arranged between the upper cover 21 and the substrate 22 and two plastic boards 24 disposed on the springs 23 for reducing the friction between the springs 23 and the upper cover 21 and the substrate board 22. First ends of the springs 23 are respectively pivotally disposed in the holes 221 formed on two sides of the substrate board 22. Second ends of the springs 23 are pivotally disposed on fixing blocks 17 formed on the upper cover 21.
Referring to FIGS. 6 to 8, when the upper cover 21 is moved downward, as shown in FIG. 7, the springs 23 are moved downward and compressed to conserve resilient energy. At this time, according to the relationship between the positions of the fixing blocks 17 and the holes 221 of the substrate board 22, the upper cover 21 is still positioned in a buffering region. Due to the elasticity of the springs 13, the upper cover 21 is kept in an upper position. However, when the fixing blocks 17 of the upper cover 21 pass over the level of the fixing holes 221 (as shown in FIG. 8), the springs 13 are further moved downward and restored from the compressed state into the original state (as shown by phantom line of FIG. 8). At this time, the resilient energy is released to locate the upper cover 21 in a lower position as shown in FIG. 8. This structure is still complicated and it is troublesome to assemble these components. As a result, the manufacturing cost is still high. Moreover, practically, after a period of use, the springs 23 tend to deform or break.